With the increasing use of portable communication devices such as cellular telephones, comes an ever increasing need to reduce the size of these devices. Portable communication devices typically consist of a singular printed circuit board having communications components as well as electrical connectors mounted on the circuit board. The electrical connectors serve several purposes. For example, an electrical connector may be used to connect external power to the circuit board. An external antenna may also be connected to the circuit board via an electrical connector. Some of these electrical connectors also take a hybrid form. The hybrid type of connectors are typically used to connect both power and signal lines to the printed circuit board from the outside. One such electrical connector is taught by Fetterolf Sr. et. al. in U.S. Pat. No. 5,693,924. That patent teaches a switching contact mechanism for use in such a portable communication device.
In order to connect an external antenna to such portable communications devices, it is often necessary to utilize a coaxial switching electrical connector so that the internal antenna can be switched out when the external antenna is connected. An electrical connector suitable for this application is taught in U.S. Pat. No. 5,693,924. That patent teaches an electrical connector including a dielectric housing having mounted therein a pair of spaced apart cantilevered switch contacts. One of the switch contacts includes a contact arm extending toward the other contact in order to affect a wiping action upon mating and unmating with the mating connector.
Another switching coaxial electrical connector is disclosed in U.S. Pat. No. 5,108,300. That patent shows an electrical connector having a pair of switch contacts wherein the first switch contact is resiliently biased in engagement against a second switch contact which is fixed. As shown in FIG. 4, the first switch contact extends beyond the second fixed switch contact. Therefore, a mating contact would engage the first switch contact and urge it away from the second fixed switch contact thus opening the switch.
A problem exists in that it is desirable to minimize the space occupied by such a switching connector, while maintaining the electrical performance characteristics necessary for such a switch. Since these connectors are typically used to pass RF signals to and from either an internal or external antenna, it is desirable to not have capacitive coupling between the switch contacts when the switch is in an open state. Typically, this problem is addressed by ensuring that the switch contacts are at a specified distance away from each other when open. In order to achieve such separation, it may be necessary to increase the size of the connector. One approach is to make both contacts movable therefore allowing each contact to move only half the required distance in order to achieve the specified separation. Since each contact is only required to move a short distance, the beam length of each contact can be reduced while maintaining an acceptable contact force between the beams. Although this reduces the size of the connector, this arrangement is disadvantages in that because both contacts move the switch contacts may not return to their original position when the switch closes. This may result in stubbing upon mating with a plug. In order to alleviate the stubbing problem, it is desirable to fix one of the switch contacts to assure the position of each contact when the switch is closed. However when fixing one contact, the movable contact will be required to travel twice the distance. This results in the requirement for a longer beam length in order to achieve the required separation and contact force. Since the contact beam length which is longer in order to have the beam exhibit the necessary spring the connector size is increased. It is therefore desirable to achieve a fixed beam switching arrangement which allows for a minimum size connector while minimizing the capacitive coupling between switch contact as is necessary for an external an antenna arrangement.